If't chance
Some curs'd example poison't near the head,
Death and disease through the whole land spread.
(Antonio, Act 1 Scene 1)

He and his brother are like plum-trees that grow crooked over standing-pools; they are rich, and o'erladen with fruit, but none but crows, pies and caterpillars feed on them.
(Bosola, Act 1 Scene 1)

Sometimes the Devil doth preach.
(Bosola, Act 1 Scene 2)

The Duchess: Diamonds are of most value,
They say, that have pass'd through most jewellers' hands.
Ferdinand: Whores, by that rule, are precious.
(Act 1 Scene 3)

Ambition, madam, is a great man's madness.
(Antonio, Act 1 Scene 3)

The misery of us that are born great!
We are forc'd to woo, because none dare woo us.
(The Duchess, Act 1 Scene 3)

I account this world a tedious theatre,
For I do play a part in't 'gainst my will.
(The Duchess, Act 4 Scene 1)

I am Duchess of Malfi still.
(The Duchess, Act 4 Scene 2)

Cover her face. Mine eyes dazzle. She died young.
(Ferdinand, Act 4 Scene 2)

She and I were twins;
And should I die this instant, I had liv'd
Her time to a minute.
(Ferdinand, Act 4 Scene 2)

I'll join with thee in a most just revenge:
The weakest arm is strong enough that strikes
With the sword of justice.
(Bosola, Act 5 Scene 2)

Whether we fall by ambition, blood or lust,
Like diamonds we are cut with our own dust.
(Ferdinand, Act 5 Scene 5)